Looking at 87 f250. Did they have both the 6.9 & 7.3 in this year? If so how do I tell them apart? Oil leakage from both valve covers. Is this a common issue. Look easy enough to change or am I dreaming?

 

1983-1987 6.9 liter
1987-1994 7.3 liter

I believe you could get them with either engine, It will tell you if it's a 7.3 or a 6.9 on the valve cover sticker via the driver side, but look at the number one injector (it's the one closest to the front on the passenger side) if it has a small in-line extention between the injector (pulse timing adapter) then that's a 7.3L. or the fuel filter will tell them apart, the 6.9 has a solid plain filter with a water seperator on the firewall. 7.3 has a two piece filter with a screw off bottom.